Journal of Applied Polymer Science, Vol.112, No.3, 1607-1614, 2009
Evaluation of Molecular Orientation in Injection Molded Parts with Microscale Features by Raman Spectroscopy
Molecular orientation of polycarbonate (PC) in injection-molded parts with microscale features was characterized by means of polarized Raman spectroscopy, and the relationship between microstructure and replication was discussed. The microscale feature size of continuous v-groove was 20 mu m in depth and 50 mu m in width. PC injection-molded parts were molded with various molding conditions. The molecular orientation distribution along flow direction on the cross-section of molding parts were evaluated by the intensity ratio of the bands at 635 to 703 cm(-1) (I-635/I-703) in the Raman spectra. Molecular orientation along the flow direction inside the v-groove was higher than that of the core and the opposite surface region. In particular, the highest molecular orientation was at the surface of the v-groove. Among the injection molding conditions, the mold temperature showed significant effect on the molecular orientation and replication. Higher mold temperature caused high replication and low molecular orientation. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 1607-1614, 2009